TABLE 2

Selected Maternal, Paternal, and Infant Characteristics of Children With or Without Early Diagnoses of ASDs by Infant Gender, 2001–2005 Massachusetts Birth Cohorts

CharacteristicsBoysGirlsBoy:Girl RatioPb
With ASDs, %Without ASDs, %ASD Cumulative IncidenceaWith ASDs, %Without ASDs, %ASD Cumulative Incidencea
Total125284.5
Maternal race/ethnicity.232
    Non-Hispanic white75.471.213274.571.3304.4
    Non-Hispanic black7.87.61278.17.5314.1
    Hispanic10.312.41048.712.5205.2
    Other6.58.8928.78.7283.3
Maternal age, y.161
    <203.75.978cccc
    20–2411.515.0959.215.0185.3
    25–2919.823.310622.623.0283.8
    30–3436.732.913934.832.9304.6
    35–3922.218.614824.818.8374.0
    40–445.54.01706.14.1434.0
    ≥450.70.2386cccc
Maternal education.415
    Some high school6.910.3845.910.4165.3
    High school graduate24.625.112222.725.3264.7
    Some college24.421.913923.521.7314.5
    ≥4 years of college44.142.712947.942.7324.0
Marital status.746
    Not married24.928.211024.228.1254.4
    Married75.171.813075.871.9304.3
Maternal primary language.749
    English93.088.813093.488.9304.3
    Not English7.011.2796.711.1174.6
Maternal nativity.606
    US born78.372.813477.373.0304.5
    Foreign born21.727.210022.727.0244.2
Paternal age, y.414
    <201.62.391cccc
    20–246.99.9896.59.9194.7
    25–2916.718.811315.418.3244.7
    30–3432.532.112932.132.3294.4
    35–3926.123.813928.524.0344.1
    40–4411.59.515311.59.6344.5
    ≥454.83.6167cccc
Parity.799
    147.044.013346.043.8304.4
    234.934.712536.434.8304.2
    ≥318.121.410617.621.4234.6
Delivery payer source.144
    Private71.065.713470.665.9304.5
    Public28.333.210627.733.0244.4
    Other0.81.1841.71.1441.9
Birth weight.002
    ≥2500 g89.093.411984.392.3264.6
    <2500 g11.06.620715.77.7583.6
Plurality.113
    Singleton90.195.611787.895.4264.5
    Twin or higher order multiple9.94.427812.24.6753.7
Prematurity.475
    Term (≥37 wk)84.089.311782.890.2264.5
    Preterm (<37 wk)16.010.718517.29.8503.7
  • a Cumulative incidence equals the number of early ASD diagnoses per 10 000 births in the study population.

  • b χ2 Comparing distributions of maternal and infant characteristics for boys with ASDs versus girls with ASDs.

  • c Suppressed because of a small cell size and for complementary cell suppression.